Aggregate risk score for predicting mortality after surgical biopsy for interstitial lung disease

In order to develop a practical risk score for 90-day mortality following surgical lung biopsy (SLB) for interstitial lung disease (ILD) we reviewed 311 consecutive patients undergoing SLB for ILD between 2002 and 2009. Postoperative complication, 30-day and 90-day mortality rates were 11.5%, 9% and 10.6% respectively. Univariable and multivariable analyses, validated by bootstrap statistics, were used to identify factors associated with 90-day mortality. A scoring system was developed by proportionally weighting the regression coefficients of the significant predictors of 90-day mortality: age >67 (P < 0.0001, weighted score 1.5), preoperative intensive care unit (ICU) admission (P = 0.006, weighted score 2), immunosuppressive treatment (P = 0.004, weighted score 1.5) and open surgery (P = 0.03, weighted score 1). Patients were grouped in four classes showing incremental risk of death at 90 days: class A, score 0 (2%); class B, score 1-2 (12%); class C, score 2.5-3 (40%); class D, score >3 (86%); P <0.0001). SLB entails a considerable surgical risk with an overall 90-day mortality around 10%. We were able to develop a practical risk score which, if validated by other independent studies, can be easily used to stratify the risk of SLB candidates and assess the cost-effectiveness of this procedure.